As a stereoscopic display device that can be viewed with naked eyes, those of a parallax barrier type and a lenticular lens type are known. The stereoscopic display devices of these types separate light using barriers or lenses, and cause different images to be visible to the right and left eyes, respectively, so as to provide a stereoscopic vision to the viewer. In recent years, main types of naked-eye stereoscopic display devices that are in the market are those of the two-viewpoint parallax barrier type and those of the lenticular lens type.
In the case of such a two-viewpoint stereoscopic display device, excellent stereoscopic display can be achieved from a predetermined region, but there also exists the following region: when a viewer moves the head to the region, a so-called crosstalk occurs, which is such a phenomenon that an image to be visible to the right eye and an image to be visible to the left eye are mixed and viewed as a double image, or a state of a so-called pseudoscopic vision occurs, which is such a phenomenon that an image to be visible to the right eye is visible to the left eye. Therefore, only from a limited region, a viewer can view stereoscopic images. To address this problem, the multiple-viewpoint technique, the tracking technique of detecting the position of the head of a viewer and displaying an image according to the position, and the like have been proposed.
Further, a technique of a switch liquid crystal display (SW-LCD) of a barrier division type has been proposed, wherein a parallax barrier is formed with a liquid crystal panel and is moved according to the position of a viewer. In the case of the SW-LCD technique, if conditions for the parallax barrier formation and the like are not appropriate, changes of luminance and increase of crosstalk occur upon the switching of the parallax barrier, in some cases.
JP2013-24957A discloses a display device that includes: a display panel on which pairs of subpixels are arrayed in a lateral direction; and a parallax barrier shutter panel on which sub-openings whose light transmitting state and light blocking state can be switchable are arrayed in the lateral direction. In this display device, among a plurality of sub-openings corresponding to a reference parallax barrier pitch, an arbitrary number of adjacent sub-openings are turned to be in the light transmitting state, and the other sub-openings are turned to be in the light blocking state, whereby integrated openings obtained are formed in the parallax barrier shutter panel. Then, the sub-opening pitch is equal to or smaller than the difference between the width of the subpixel and the width of the integrated opening.